Impact of HZSM-5 supported Fe, Ni, and Mo catalysts on microcrystalline cellulose liquefied bio-oil composition

The effects of Fe, Ni, and Mo active components loaded with HZSM-5 on the composition of hydrothermal liquefaction bio-oil from microcrystalline cellulose were investigated. All three supported catalysts resulted in the cyclization of microcrystalline cellulose into aromatic compounds. Additionally, Fe/HZSM-5 underwent oxidation, producing ketones, aldehydes and carboxylic acids, which accounted for 44.5% of the total composition of bio-oil. On the other hand, Ni/HZSM-5 and Mo/ZHSM-5 caused ring-opening of microcrystalline cellulose, leading to the production of alcohols and hydrocarbons, constituting 23.05% and 36.46% of the total composition, respectively. These findings indicate that the catalysts not only facilitated the ring-opening of polycyclic rings in microcrystalline cellulose but also underwent reactions with the hydroxyl groups present. To further understand the impact of these catalysts on hydroxyl groups similar to microcrystalline cellulose, glycerol was used as a model compound for liquefaction. The results revealed that 40.72% of Fe/HZSM-5 bio-oils consisted of cyclic ketones, while Ni/HZSM-5 predominantly produced straight-chain alkanes, straight-chain lipids, and straight-chain carboxylic acids. In contrast, Mo/HZSM-5 primarily yielded six-membered cyclic carboxylic acids, accounting for 72.48% of the composition.